Akai AA-39
The Akai AA-39 is an integrated stereo amplifier, part of Akai's range of audio equipment, popular in the 1990s.
General Specifications
Maximum power (8Ω): 45WFrequency response (-3dB): 10Hz-60kHz
THD+N: 0.008%
Signal to noise ratio (Line): 99dB
Signal to noise ratio (Phono): 81dB
Residual noise: 0.1mV
Input sensitivity (Line): 150mV
Input sensitivity (Phono): 2mV
Chanel separation (Line): 65dB
Crosstalk (Line): 90dB
Damping factor: 65
Speaker load impedance: 4Ω-16Ω
Dimensions (WHD): 425×156×370mm
Weight: 11.3kg
Produced: 1995-1996
Measured Values
Maximum power (8Ω): 40WFrequency response (20Hz-20kHz): ±0.3dB
Channel imbalance: <0.5dB
THD (1kHz, 1W): 0.0032%
THD+N (1kHz, 1W): 0.015%
THD (1kHz, 20W): 0.0062%
THD+N (1kHz, 20W): 0.0093%
IMD (70Hz, 5kHz, 1W): 0.017%
Noise: -71.1dB
Amplification: 123.3
DC offset L: -6.0mV
DC offset R: -4.0mV
Maximum Power
Maximum power is measured using 8Ω resistors on both channels. A 1kHz sine wave input signal is applied and gradually increased until higher harmonics rise significantly. Typically, this is the point at which output clipping occurs.
Frequency Response
Frequency response is measured using several equilizer settings. 'Flat' indicates the tone controls are either turned off or set to their neutral position. 'Max' and 'Min' refer to the maximum and minimum tone control positions, respectively. In the phono section, the expected response follows the RIAA equalization curve.
Residual Noise
These graphs display the noise levels at various volume positions. To eliminate any interference from the input signal, the input lines are shorted during the measurement. Generally, the noise is highest at the mid-point of the volume range (50%)
Distorsion
Total harmonic distortion (THD) is measured using a 1kHz sine wave input, with the output level adjusted to meet different conditions. Intermodulation distortion (IMD) is measured using 'two sine' input signal. THD versus voltage is measured with a 1kHz sine wave input, while THD versus frequency is measured at various output levels.
